Typically, trailers are designed to be used for one type of hauling and mounted to a certain type of vehicle. For example, trailers that are mounted to ATVs usually have a short distance between the trailer and the vehicle, to maximize maneuverability in confined spaces and minimize the amount of travel in the trailer when in operation. However, a short distance between the trailer and the vehicle is not ideal for hauling a load on paved or maintained roadways, since it is more difficult to maneuver the trailer, especially when operating the vehicle in reverse. Moreover, the height of a hitch on a vehicle may vary from vehicle to vehicle, thus requiring a trailer with a hitch coupler positioned at a corresponding height. This is particularly problematic when a single trailer is to be used for hauling behind both a lawn tractor and a full-sized pickup truck. Therefore, individuals who own full-sized vehicles as well as ATVs and use both for hauling often have at least two trailers to suit the individual requirements of each vehicle.
The concept of providing adaptable trailers or tow bars is well known in the art. U.S. Pat. Nos. 1,649,084; 2,174,468 and 2,481,685 all teach of tow bars that are compact for easy storage and transportation that can be extended when required. Furthermore, U.S. Pat. No. 3,829,131 teaches of a aircraft tow bar that can folded for compact storage purposes. However, none of these devices can be used in their compact configuration for towing purposes.
U.S. Pat. No. 1,422,129 teaches of a wishbone tow bar attached to a farm implement which is transformable from a short configuration, ideal for towing behind a tractor, to a longer configuration suitable for connecting to horse or some form of large animal. The wishbone tow bar described in this patent document cannot be attached for use on conventional single point hitches.
U.S. Pat. No. 1,422,129 teaches of a wishbone tractor coupling attached to a farm implement which is transformable from a short configuration, ideal for towing behind a tractor, to a longer configuration suitable for connecting to horse or some form of large animal. The wishbone tractor coupling described in this patent document cannot be attached for use on conventional single point hitches.
U.S. Pat. Nos. 5,722,678 and 6,302,425 both describe convertible trailer coupling devices. U.S. Pat. No. 5,722,678 teaches of a coupling device with two hitch eyes of different diameters attached to the ends of a draw bar, which can be pivoted about a vertical axis in a horizontal plane. The distance between the pivot axis and the ends of the draw bar are equally spaced. U.S. Pat. No. 6,302,425 teaches of a trailer with a tongue with two couplers of different length. The short tongue is stationary, whereas the long tow bar pivots about a vertical axis in a horizontal plane. The long tongue is secured along the side of the trailer when not in use.
German Patent No. 7332914 teaches of a convertible tongue and coupler for providing different distances between the body of the trailer and the vehicle. The length of the tongue can be converted from a short configuration to a long configuration by pivoting in a vertical plane about a horizontal axis provided in a frame, so that the tongue lies in a plane fixed by the frame. This configuration of the tongue does not allow for the trailer to be coupled to different vehicles with varying hitch heights. Moreover, German Patent No. 7332914 teaches the use of only hitch eyes as the hitch couplers.